Module for air conditioning the interior of a camper van or similar vehicle.

Abstract

Module (4) for air conditioning an interior (1) of a caravan (2) or similar, with - an internal air duct (10) in which an internal heat exchanger (12) is arranged, which is designed to interact with air from the interior of the caravan, - an outside air duct (20) in which an outside heat exchanger (22) is arranged, which is designed to interact with outside air, - a transfer opening (34) which is arranged in a partition (32) between the inner air duct (10) and the outer air duct (20) downstream of the inner heat exchanger (12) and upstream of the outer heat exchanger (22), - a switching element (36) that can close or open the overflow opening (34), and - with a condensate element (46) to which heat energy can be supplied from the inner air duct (10).

Description

[0001] The invention relates to a module for air conditioning the interior of a caravan or similar, which uses a heat pump.

[0002] A heat pump can be used to heat a caravan, motorhome, camper, ship's cabin, etc. with minimal energy consumption. If necessary, the module can also be used in reverse as an air conditioning system for cooling.

[0003] A key problem when using heat pumps in such mobile living spaces is the icing of the evaporator at low outside temperatures.

[0004] If an air conditioner is used in heat pump mode for heating and the outside temperature is around freezing, the humidity condenses on the cold evaporator and freezes over time. A layer of ice or snow forms on the evaporator fins and tubes. This ice formation blocks the airflow through the evaporator, leading to a drop in performance and impairing the unit's function. If the ice builds up heavily, the heat pump can no longer operate at all. To ensure the proper functioning of the heat pump, heavy icing must be prevented or the evaporator must be defrosted periodically.

[0005] Since icing often cannot be completely prevented, it is common practice to defrost the evaporator cyclically. This requires thermal energy to be introduced into the evaporator to melt the ice. The most common methods for air-to-air heat pumps today are hot gas bypass defrosting and reverse cycle defrosting.

[0006] In hot-gas bypass defrosting, hot refrigerant is directed directly from the compressor to the evaporator. However, only the energy that the compressor converts into heat energy during the compression process is available for defrosting. In reverse-cycle defrosting, the refrigeration circuit is reversed using a four-way valve. The functions of the heat pump and air conditioning system are reversed; the evaporator becomes the condenser and vice versa. This allows thermal energy from the interior to be used for defrosting in addition to the compressor energy.

[0007] A disadvantage of reverse-cycle defrosting is that, since the air conditioner operates as an air conditioner for several minutes, it blows cold air into the living space. This occurs at a time when the user expects warm air to be blown in. This can be irritating to the user. In addition, when switching from heat pump to air conditioner operation and back, the system takes several minutes to reach full capacity in each operating mode, which increases the time until maximum defrosting and then maximum heating can be achieved again. This disadvantageous switching process and the lack of heating output are system-related disadvantages of both hot gas defrosting and reverse-cycle defrosting.

[0008] US Pat. No. 4,459,816 discloses a heat pump installed in a building. It is used to heat water in a hot water tank located within a room of the building. The heat pump's condenser is located in this room and transfers the heat to a cold water pipe, thereby heating the water in the tank. This system can be used to heat domestic water or for central heating. When the heat pump is operated at low outside temperatures, frost can form on the evaporator. To defrost the evaporator when necessary, a flow channel can be opened to direct room air over the evaporator. It is also mentioned that the evaporator can be used to heat the room air.

[0009] DE 31 42 621 A1 discloses a method and device for improving the defrosting of evaporators and drain trays in air handling units with heat pumps. The warm exhaust air from a heated unit is used to effectively defrost both the evaporator and the drain tray below it. In conventional heat recovery systems with heat pumps, ice often forms on the evaporators and in the drain trays at low outside temperatures, which can impair the operational reliability and efficiency of the system. To prevent a layer of ice from forming on the drain trays, warm exhaust air from the system is directed along the underside of all drain trays. This heats the drain trays, prevents unwanted ice buildup, and melts any existing ice without the need for additional heating elements.The exhaust air then flows upwards between the drainage troughs and is directed to the desired evaporator via a flap. By adjusting the flap, the exhaust air can be directed through either evaporator, enabling targeted defrosting.

[0010] EP 2 611 634 A1 discloses a vehicle air conditioning system in which, in the event of an iced-up exterior heat exchanger, warm refrigerant, after flowing through the interior heating condenser, is directed directly to the exterior heat exchanger to defrost it. This method enables effective defrosting of the evaporator, as the warm refrigerant melts the ice formed on the exterior heat exchanger. This ensures that the evaporator operates reliably even at low temperatures, without the need for additional components or significant energy consumption.

[0011] US 2024 0068736 A1 discloses a heat pump with a special condensate management system that prevents the accumulation of freezing water during heating operation. A tray located below the evaporator directs the produced condensate directly to a lower drain tray. The first tray acts as a barrier that prevents condensate from reaching other components such as the fan or motor, thereby reducing the risk of frost formation. Additionally, a temperature-controlled drain device is used, which is activated at certain temperatures to drain the condensate and thus prevent ice formation on the evaporator.

[0012] DE 10 2013 106 209 A1 discloses a method and device for detecting and preventing icing of an evaporator in an air conditioning system. The current consumption of a fan assigned to the evaporator is measured to determine the electrical power consumption required to move air through the evaporator. When icing begins, the flow resistance at the evaporator's heat transfer surface increases, leading to a reduced air volume and thus to lower fan power consumption. By comparing the current power consumption with a setpoint determined from the fan's characteristic curve, incipient icing can be detected. If the power consumption falls below the setpoint, measures are initiated to prevent icing, or active defrosting is started.This process makes it possible to maintain the heat pump function of the air conditioning system continuously without risking interruptions in operation due to icing.

[0013] The object of the invention is to provide a module for air conditioning the interior of a caravan or similar, which has a heat pump that can be operated with low energy consumption and whose operation is not impaired by icing.

[0014] To achieve this object, the invention provides a module for air conditioning the interior of a caravan or similar, comprising an interior air duct in which an interior heat exchanger is arranged, which is intended to interact with air from the interior of the caravan, an exterior air duct in which an exterior heat exchanger is arranged, which is intended to interact with exterior air, an overflow opening arranged in a partition wall between the interior air duct and the exterior air duct downstream of the interior heat exchanger and upstream of the exterior heat exchanger, a switching element that can close or open the overflow opening, and a condensate element to which thermal energy from the interior air duct can be supplied. The particular advantage of the module according to the invention is that the evaporator can be defrosted with little effort while the heat pump can continue to operate continuously.Simply by opening the overflow opening, a (usually, but not necessarily smaller) portion of the generated warm air is diverted and passed through the outdoor heat exchanger, which operates as an evaporator and is defrosted using the heat thus introduced. At the same time, a (usually, but not necessarily larger) portion of the total warm air provided can be directed into the interior to be heated. The user may at most notice that temporarily, namely for the period of defrosting, slightly less warm air reaches the interior. Overall, however, there is no loss of comfort during defrosting, as the heat pump can operate continuously. In addition, the transfer of thermal energy from the "warm air side" of the module to the condensate element ensures that there are no problems with icing there.

[0015] In one embodiment of the invention, the switching element is adjustable between a position in which the overflow opening is completely closed and a position in which an outside air inlet to the outside air duct is closed. By closing the outside air inlet, the outside heat exchanger is completely "cut off" from the cold outside air, thus accelerating defrosting.

[0016] In one variant of the invention, a fan is arranged in each of the indoor air ducts and the outdoor air ducts. The advantage of this arrangement is that the air flow can be regulated independently of each other thanks to separate fans in each of the air ducts. This leads to improved energy efficiency and enables precise adjustment of the air flow to the respective operating conditions, thus increasing comfort for the user. In particular, by controlling the two fans, even when the switching element is fully open, it is possible to adjust the proportion of warm air directed into the interior and the proportion of warm air used to defrost the outdoor heat exchanger.

[0017] In a further embodiment of the invention, a distribution flap is provided in the interior air duct, allowing the air flow to be distributed between a first and a second interior air outlet. This allows the air flow within the interior to be controlled in a targeted manner. The distribution flap makes it possible to individually air-condition different areas of the interior, resulting in increased comfort and efficient use of thermal energy.

[0018] In one variant of the invention, an air intake opening, which is associated with an air intake damper, is provided in a partition wall between the outside air duct and the inside air duct. The advantage of this design is that, when the air intake damper is open, fresh outside air can be introduced into the inside air duct and thus into the interior in a controlled manner. This improves the air quality in the interior and enables demand-based ventilation.

[0019] In one embodiment of the invention, the supply air opening opens downstream of the distribution flap in the interior air duct. This ensures that the supply air, which is usually rather cold, is directed to outlet openings located at the top of the interior, thus distributing the supply air throughout the interior and preventing temperature stratification.

[0020] In a further embodiment of the invention, a heat-conducting element is provided, which is associated with the switching element and extends from the indoor air duct into the outdoor air duct. The advantage of this design is that heat energy can be efficiently transferred from the warm indoor air duct to the cooler outdoor air duct. This heat energy can be used to passively prevent ice formation on the condensate element.

[0021] In one embodiment of the invention, the condensate element is designed as a condensate tray associated with the outdoor heat exchanger. The condensate tray has at least one air outlet that communicates with the indoor air duct downstream of the indoor heat exchanger. Through this flow connection, a small portion of the warm air from the indoor air duct can be diverted, which is used to heat specific areas of the condensate tray. This specifically prevents icing in those areas.

[0022] In one embodiment, the condensate element is a separate plastic component located within the heat pump, ensuring that any condensate accumulating there can be collected and drained as desired. However, the condensate element can also be integrated or even formed integrally with the housing of the air conditioning module. For example, the contour of the condensate element can be molded directly into the module housing, creating a trough-like structure. The housing can be made of EEP (expanded polypropylene), for example.

[0023] In one variant of the invention, the air outlet surrounds a condensate drain opening. The advantage of this design is that the warm air is directed directly around the condensate drain opening, preventing the condensate outlet from freezing. This ensures continuous and uninterrupted drainage of the condensate.

[0024] In a further embodiment of the invention, the air outlet is associated with the switching element. This prevents ice from forming on the switching element, which could impair its functionality.

[0025] In one embodiment of the invention, the air outlet is assigned to the outdoor heat exchanger. The advantage of this arrangement is that the warm air is directed specifically to the outdoor heat exchanger, effectively preventing or eliminating icing. This increases the efficiency of the defrosting process and minimizes interruptions in heating operation.

[0026] In one variant of the invention, the air outlet is associated with an outside air inlet. The technical advantage here is that warm air protects the outside air inlet from icing. This keeps the air inlet always clear, improving the performance of the outside air duct and thus the efficiency of the entire system.

[0027] In a further embodiment of the invention, a hot air guide duct is arranged beneath a bottom surface of the condensate tray. The advantage of this design is that the heat from the hot air is guided directly beneath the condensate tray. This prevents the condensate from freezing on the bottom surface of the tray and ensures reliable drainage of meltwater, thus increasing operational reliability.

[0028] The invention is described below with reference to various embodiments illustrated in the accompanying drawings. In the drawings: - Fig. 1 shows a section through a module according to the invention installed in an interior space to be heated, the module being operated as a heat pump; - Fig. 2 the module of Fig. 1, where it operates as a heat pump and the evaporator is defrosted; - Fig. 3 the module of Fig. 1 a variant with a vertically arranged external heat exchanger, whereby the module is operated as a heat pump; - Fig. 4 the module of Fig. 3, where it operates as a heat pump and the evaporator is defrosted; - Fig. 5 the module according to a second embodiment, wherein it is operated as a heat pump and warm air is discharged via a first interior air outlet; - Fig. 6 the module of Fig. 5, wherein it operates as a heat pump and warm air is discharged via a second interior air outlet; - Fig. 7 the module according to a third embodiment, wherein it is operated as a heat pump; - Fig. 8 the module of Fig. 7, wherein it is operated to supply fresh air to the interior; - Fig. 9 the module of Fig. 7, where it is used to dry the air in the interior; - Fig. 10 a section of the module of Fig. 1, showing details of the condensate drainage; - Fig. 11 a section of the module of Fig. 2, showing details of the condensate drainage; - Fig. 12 a section of the module of Fig. 3, showing details of the condensate drainage; - Fig. 13 a section of the module of Fig. 4, showing details of the condensate drainage; - Fig. 14 in a perspective cut view of a condensate tray, which is located in the module of the Fig. 10 to 13 is used; Fig. 15 the condensate tray of Fig. 14 in a perspective view from above; - Fig. 16 the condensate tray of Fig. 14 in a perspective view from below; - Fig. 17 a section of the module of Fig. 1, showing details of a heat-conducting element for preventing icing; and - Fig. 18 a section of the module of Fig. 3, showing details of a heat conducting element for preventing icing.

[0029] Based on Fig. 1 describes the structure of a module for air conditioning the interior 1 of a caravan 2, a motorhome, a camper, a ship's cabin, etc. Generally speaking, the module comprises a heat pump that can be electrically operated to supply warm air to the interior. If necessary, the module can also be operated conversely as an air conditioning system for cooling, supplying cold air to the interior.

[0030] The individual components of the heat pump are explained below only to the extent that they are necessary to understand how the module works.

[0031] The module is generally designated by reference numeral 4. It is assigned to the interior 1 of the caravan 2 or similar. In the embodiment shown, it is designed as a compact assembly arranged in a housing 6.

[0032] Within the housing 6, an internal air duct 10 is formed, in which an internal heat exchanger 12 is arranged. The internal heat exchanger 12 is designed to interact with air from the interior of the caravan. When the module 4 is operated as a heat pump, the internal heat exchanger 12 acts as a condenser, transferring heat to the air flowing through it. When the module 4 is operated as an air conditioning system, the internal heat exchanger 12 acts as an evaporator, extracting heat from the air flowing through it.

[0033] An internal fan 14 is arranged in the internal air duct, with which the air mass flow through the internal air duct can be controlled.

[0034] In the embodiment shown, the internal fan 14 is arranged downstream of the internal heat exchanger 12.

[0035] The module 4 has an interior air inlet 16 and an interior air outlet 18, which are assigned to the interior space 1 and (at least for a large part of the operating modes of the module 4) represent the beginning and the end of the interior air duct 10 through which the interior air flows.

[0036] Also formed within the housing 6 is an outside air duct 20, in which an outside heat exchanger 22 is arranged. The outside heat exchanger 22 interacts with outside air to absorb or release heat energy. When the module 4 is operated as a heat pump, the outside heat exchanger 22 acts as an evaporator, extracting heat from the air flowing through it. When the module 4 is operated as an air conditioner, the outside heat exchanger 22 acts as a condenser, transferring heat to the air flowing through it.

[0037] An external fan 24 is arranged in the external air duct 20, with which the air mass flow through the external air duct 20 can be controlled.

[0038] In the embodiment shown, the outdoor fan 24 is arranged downstream of the outdoor heat exchanger 22.

[0039] Module 4 has an outside air inlet 26 and an outside air outlet 28 that lead to the outside of the caravan or similar, i.e., they are either formed directly in an exterior wall of the caravan or similar (in the illustrated embodiment, in a floor 30) or are in fluid communication with the outside environment. The outside air inlet 26 and the outside air outlet 28 represent (at least for most of the operating modes of module 4) the beginning and end of the outside air duct 20 through which the outside air flows.

[0040] The indoor air duct 10 and the outdoor air duct 20 are separated from each other by a partition wall 32. An overflow opening 34 is arranged in this partition wall 32, which is located downstream of the indoor heat exchanger 12 and upstream of the outdoor heat exchanger 22.

[0041] The overflow opening 34 is assigned a switching element 36 with which the overflow opening 34 can be selectively closed or opened.

[0042] The switching element 36 can be designed as a flap.

[0043] A drive for the switching element 36, for example an actuator, is not shown here.

[0044] In Fig. 1 shows the module in “heating” operating mode.

[0045] In heating mode, the room air is drawn into the interior air duct 10 via the interior air inlet 16. There, the air flows through the interior heat exchanger 12, which acts as a condenser and heats the air. The downstream interior fan 14 then expels the heated air through the interior air outlet 18 back into the interior 1, thereby heating it.

[0046] At the same time, outside air is drawn into the outside air duct 20 by the outside fan 24 via the outside air inlet 26. The air flows through the outside heat exchanger 22, which acts as an evaporator and extracts heat from the outside air. The outside fan 24 returns the cooled outside air to the outside environment through the outside air outlet 28.

[0047] The refrigerant circuit of the heat pump (not shown here) transports the absorbed heat energy from the outdoor heat exchanger 22 to the indoor heat exchanger 12. In the outdoor heat exchanger 22, the refrigerant evaporates due to the absorbed heat and then condenses in the indoor heat exchanger 12, releasing the heat to the indoor air.

[0048] In heating mode, the switching element 36 is in the Fig. 1, in which the overflow opening 34 is completely closed. This ensures that the maximum heating output is available for the interior.

[0049] The described module 4 can also be operated in reverse, i.e., as an air conditioning system, with the indoor heat exchanger 12 acting as an evaporator and the outdoor heat exchanger 22 acting as a condenser. In this way, the interior 1 can be cooled at high outside temperatures.

[0050] If it is detected that the outdoor heat exchanger 22 is iced up, the module is Fig. 1 in a “heating with simultaneous defrosting” operating mode. This operating mode is in Fig. 2 shown.

[0051] In the "heating with simultaneous defrosting" operating mode, the switching element 36 is fully open, thereby releasing the overflow opening 34 between the indoor air duct 10 and the outdoor air duct 20. At the same time, the switching element 36 closes the outdoor air inlet 26, preventing cold outside air from flowing into the outdoor air duct 20.

[0052] In this operating mode, a portion of the warm air flow available downstream of the indoor heat exchanger is “tapped” and directed through the overflow opening 34 to the outdoor heat exchanger so that any ice present there is defrosted.

[0053] At the same time, part of the warm air is conveyed back into the interior 1 by the interior fan 14 via the interior air outlet 18, whereby the interior continues to be heated.

[0054] The volume fractions of the warm air flow used to heat the interior 1 and to defrost the exterior heat exchanger 22 can be adjusted by the ratio of the speeds of the interior fan 14 and the exterior fan 24. The higher the speed of the exterior fan 24 relative to the speed of the interior fan 14, the more warm air is available for defrosting and the less warm air is available for heating the interior 1.

[0055] To replace the air volume expelled from the interior 1 via the outside air outlet 28, a compensating opening 38 is provided in the caravan 2 or similar device, through which air can flow when the pressure in the interior 1 drops below ambient pressure. The compensating opening 38 can operate purely passively, for example, with slats that close automatically due to gravity, or it can be actively controlled, with flaps or slats being adjusted between a closed and an open position.

[0056] When the outdoor heat exchanger 22 has defrosted, the overflow opening 34 is closed again and all of the warm air is again available for heating the interior 1.

[0057] In the Fig. 3 and Fig. Figure 4 shows a variant embodiment. The same reference numerals are used for components known from the first embodiment, and reference is made to the above explanations.

[0058] The version of the Fig. 3 and Fig. 4 differs from the design of the Fig. 1 and Fig. 2 in that the external heat exchanger 22 is not arranged obliquely overhanging to the front, but standing vertically.

[0059] The functionality in the operating module “Heating” and “Heating with defrosting” corresponds to the functionality of the embodiment of the Fig. 1 and Fig. 2.

[0060] In the Fig. 5 and Fig. Figure 6 shows a second embodiment based on the first embodiment. The same reference numerals are used for components known from the first embodiment, and reference is made to the above explanations.

[0061] The design of the Fig. 5 and Fig. 6 differs from the design of the Fig. 1 and Fig. 2 in that a distribution flap 40 is provided, with which the air flow can be switched between an upper interior air outlet 18o and a lower interior air outlet 18u. This arrangement makes it possible to direct the heated or cooled air specifically into different areas of the interior 1, thus increasing comfort for the users.

[0062] The indoor air duct 10 branches downstream of the indoor heat exchanger 12 into two separate air outlets: an upper indoor air outlet 18o and a lower indoor air outlet 18u. The distribution flap 40 is arranged so that it can distribute the air flow either completely to the upper outlet 18o, the lower outlet 18u, or to both outlets simultaneously.

[0063] By adjusting the distribution flap 40, the user can choose whether the air is directed predominantly upwards or downwards. In heating mode, for example, the warm air can be blown in via the lower interior air outlet 18u near the floor, from where it rises evenly and effectively heats the interior 1. Alternatively, the air can be blown into the upper area of ​​the interior via the upper interior air outlet 18o, which is particularly advantageous when module 4 is operated as an air conditioning system.

[0064] The piping from module 4 to the actual air outlets, which are arranged on the walls of the caravan or similar, is not shown here.

[0065] The distribution flap 40 can be operated manually or motor-driven via an actuating mechanism. In a motor-driven version, the distribution flap 40 can be controlled automatically via a central control system of module 4, depending on the set climate profiles.

[0066] It is also possible to use the various air outlets to specifically air-condition different areas of the caravan, for example a living area and a sleeping area.

[0067] In the Fig. 7 and Fig. Figure 8 shows a third embodiment based on the first embodiment. The same reference numerals are used for components known from the first embodiment, and reference is made to the above explanations.

[0068] The design of the Fig. 7 and Fig. 8 differs from the design of the Fig. 1 and Fig. 2 in that an air supply opening 42 is provided in the partition wall 32, to which an air supply flap 44 is assigned.

[0069] If the supply air damper 44 is closed (see Fig. 7), the module 4 operates in the same manner as explained above for the module according to the first embodiment.

[0070] If the supply air damper 44 is open (see Fig. 8), the distribution flap 40 is preferably closed simultaneously. By means of the external fan 24, air can be introduced from outside the interior space 1 through the outside air inlet 26 into the interior space 1. The introduced air volume can flow out through the equalizing opening 38.

[0071] The design of the Fig. 7 and Fig. Module 8 is particularly suitable for pre-conditioning the interior 1, for example, when it has become very hot. If the warm air is first displaced from the interior of a caravan or similar vehicle, less energy is subsequently required to condition the interior using module 4 (in "cooling" mode).

[0072] In Fig. 9 is another operating mode of module 4 of Fig. 7 shown.

[0073] Here, the module is operated in the "dehumidification" mode, in which the supply air flap 44 is closed but the overflow opening 34 is open. The indoor fan 14 and / or the outdoor fan 24 draw in the air from the interior 1 through the indoor air inlet 16, causing it to flow through the indoor heat exchanger 12. The indoor heat exchanger 12 is operated as an evaporator, so that the air flowing through it is cooled and dehumidified. The dehumidified air is then directed by the outdoor fan 24 and / or the indoor fan 14 over the outdoor heat exchanger 22, now operating as a condenser, and heated.

[0074] If desired, the temperature of the air can be kept essentially constant here, since the air is first cooled as it flows through the indoor heat exchanger 12 before it is heated as it flows through the outdoor heat exchanger 22.

[0075] Based on the Fig. 10 to 13, the condensate drainage in the modules according to the previously described embodiments is explained in detail. Fig. 10 and Fig. 11 on the design of the Fig. 1 and Fig. 2, while the Fig. 12 and Fig. 13 on the design of the Fig. 3 and Fig. 4.

[0076] Fig. 10 shows a section of module 4 from Fig. 1, showing details of the condensate drainage system. A condensate element, designed here as a condensate pan 46, is located below the outdoor heat exchanger 22. It serves to collect the condensate forming on the outdoor heat exchanger 22 and reliably drain it to the outside.

[0077] The basic feature of the condensate element is that it can be supplied with heat energy from the indoor air duct 10 in order to prevent ice formation or to thaw ice.

[0078] When designing the Fig. 10, 11, and 14 to 16, a hot air duct 48 (symbolized here by the warm air flow) is arranged below the bottom surface 50 of the condensate tray 46. A portion of the warm air from the interior air duct 10 is diverted through this hot air duct 48. The warm air flows beneath the condensate tray 46 and heats it, preventing the collected condensate from freezing.

[0079] The condensate tray 46 is provided with recesses 52 associated with the outside air inlet 26. Each of the recesses 52 is provided with a collar 54 that seals off the floor 30, so that the hot air guide channel 48 is defined between the floor and the underside of the condensate tray 46.

[0080] Small outlets 56 for warm air are provided around the recesses 52. Some of the outlets 56 are located near the switching element 36, so that it is heated when closing the overflow opening on the "cold side" and thus protected from icing. Likewise, a sealing surface between the condensate pan 46 and the switching element 36 is kept ice-free.

[0081] A portion of the outlets 56 is assigned to the outdoor heat exchanger 22 so that it is heated and protected from icing.

[0082] The condensate tray 46 also has a condensate drain opening 58 through which the collected condensate is drained to the outside through the base 30. A further outlet 56 for warm air is provided around the condensate drain opening 58. This prevents the condensate drain opening 58 from becoming blocked by ice formation.

[0083] If module 4 is operated in “heating with simultaneous defrosting” mode (see Fig. 11), the switching element 36 is open, allowing warm air from the indoor air duct 10 to flow through the overflow opening 34 into the outdoor air duct 20 to defrost the outdoor heat exchanger 22. In this case, the switching element 36 closes not only the recesses 52 but also the outlets 56 arranged around the recesses. Since a large amount of warm air flows over the open switching element in this state, sufficient heat energy is introduced to prevent icing.

[0084] The Fig. 12 and Fig. 13 show the condensate tray 46 for the Fig. 3 and Fig. 4. Reference is made to the explanations above.

[0085] In the Fig. 14 to 16 show the individual elements of the condensate tray 46, in particular the hot air guide channel 48 (in an exemplary sectional plane), the base surface 50, the recesses 52, the collars 54, the outlets 56 for hot air (also called air outlets) and the condensate discharge opening 58.

[0086] In Fig. 17 shows a variant based on the module of the Fig. 1 and Fig. 2. A heat conducting element 60 is provided, which extends from the indoor air duct 10 into the outdoor air duct 20, i.e. from the warm air side to the cold air side (when considering an operating mode as a heat pump).

[0087] The heat-conducting element 60 can be made of a material with good heat conductivity, such as an aluminum alloy. The heat-conducting element 60 can also be designed in the form of a condensate element.

[0088] Due to the heat input, the mechanical function of the switching element 36 and the sealing effect of the switching element 36 are maintained, and the condensate discharge opening 58 remains free of ice.

[0089] In Fig. 18 is the version of Fig. 17 for the variant of module 4 with vertically positioned outdoor heat exchanger 22. The functionality is the same as for the module of Fig. 17.

[0090] The module 4 according to the invention is operated in such a way that both efficient air conditioning of the interior 1 and reliable defrosting of the external heat exchanger 22 are ensured.

[0091] The module is controlled by a central control unit, which monitors various parameters and initiates appropriate measures as needed. Various sensors and measurement methods are used to detect icing on the outdoor heat exchanger 22. One or more temperature sensors measure the surface temperature of the heat exchanger; if this temperature falls below a certain threshold, for example, 0 °C, it can be concluded that ice formation is beginning.

[0092] Furthermore, the pressure loss before and after the outdoor heat exchanger 22 is monitored by sensors. An increase in the differential pressure indicates reduced air permeability, which may be caused by ice formation.

[0093] If the evaporation pressure in the refrigerant circuit drops below a certain value, this can also serve as an indicator of icing. Environmental data such as the outside temperature and humidity can also be used. At temperatures around freezing, especially between +5 °C and -5 °C, humidity is often high, which can lead to increased ice formation.

[0094] If icing is detected or expected due to the ambient conditions, the control unit switches module 4 to the operating mode “heating with simultaneous defrosting” (see Fig.2). The switching element 36, which is designed as a motor-driven flap, is fully opened, thereby exposing the overflow opening 34 and simultaneously closing the outside air inlet 26. This prevents cold outside air from being drawn in. A portion of the inside air heated by the inside heat exchanger 12 is now directed through the overflow opening 34 into the outside air duct 20. The warm air flows over the iced-up outside heat exchanger 22 and melts the ice. The remaining portion of the warm air continues to be conveyed by the inside fan 14 via the inside air outlet 18 into the interior 1, so that heating continues without interruption.

[0095] The duration of the defrosting process can be set in different ways. Sensor-based methods end the defrosting process when the sensors indicate that the icing has been eliminated, for example, when the temperature at the outdoor heat exchanger 22 rises above a certain value or the differential pressure returns to normal. Alternatively or additionally, the defrosting process can be automatically terminated after a predefined period of time, such as two minutes. Under critical environmental conditions, it is also possible to activate defrosting preventively at regular intervals, for example, every ten minutes.

[0096] During the defrosting process, various operating parameters can be adjusted. The speeds of the interior fan 14 and the exterior fan 24 are controlled to achieve optimal airflow for defrosting without significantly impairing the interior heating.

[0097] The switching element 36 can be adjusted to intermediate positions to optimize the ratio of heating to defrosting. A key advantage of this process is that the heat pump remains in heating mode throughout the entire defrosting process, continuously providing warm air. Unlike conventional processes such as reverse-cycle defrosting or hot-gas defrosting, in which heating operation is interrupted or reduced, the user experiences no loss of comfort.

[0098] The technical implementation includes a motorized flap adjustment of the switching element 36, which is connected to an electric motor and controlled by the control unit, allowing the flap to be positioned precisely. The sensor system consists of temperature and pressure sensors located at strategic locations in Module 4, which provide real-time data to the control unit. A programmed algorithm evaluates the sensor data and decides on the necessity and duration of defrosting based on predefined thresholds and empirical values.

[0099] The described method enables effective and efficient defrosting of the outdoor heat exchanger 22 without compromising the heating comfort in the interior 1. The continuous supply of warm air and the intelligent control of the operating parameters achieve high efficiency and increase the service life of the module 4. The heat pump continues to run during the defrosting process and can provide warm air at the outlets, which represents a significant advantage over known methods in which heating operation must be cyclically interrupted. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 4,459,816

[0008] DE 31 42 621 A1

[0009] EP 2 611 634 A1

[0010] US 2024 0068736 A1

[0011] DE 10 2013 106 209 A1

[0012]

Claims

[1] Module (4) for air conditioning an interior (1) of a caravan (2) or similar, with - an internal air duct (10) in which an internal heat exchanger (12) is arranged, which is intended to interact with air from the interior of the caravan, - an outside air duct (20) in which an outside heat exchanger (22) is arranged, which is intended to interact with outside air, - an overflow opening (34) arranged in a partition wall (32) between the indoor air duct (10) and the outdoor air duct (20) downstream of the indoor heat exchanger (12) and upstream of the outdoor heat exchanger (22), - a switching element (36) which can close or open the overflow opening (34), and - with a condensate element (46) to which heat energy can be supplied from the internal air duct (10). [2] Air conditioning module according to claim 1, characterized bythat the switching element (36) is adjustable between a position in which the overflow opening (34) is completely closed and a position in which an outside air inlet (26) to the outside air duct (20) is closed. [3] Air conditioning module according to claim 1 or claim 2, characterized by that a fan (14, 24) is arranged in each of the internal air duct (10) and the external air duct (20). [4] Air conditioning module according to one of the preceding claims, characterized by that a distribution flap (40) is provided in the internal air duct (10), with which the air flow can be distributed between a first and a second internal air outlet (18o, 18u). [5] Air conditioning module according to one of the preceding claims, characterized by that an air supply opening (42) is provided in a partition wall (32) between the outside air duct (20) and the inside air duct (10), to which an air supply flap (44) is assigned. [6] Air conditioning module according to claim 4 and claim 5, characterized by that the supply air opening (42) opens into the internal air duct (10) downstream of the distribution flap (40). [7] Air conditioning module according to one of the preceding claims, characterized by that a heat-conducting element (60) is provided which is assigned to the switching element (36) and extends from the inner air duct (10) into the outer air duct (20). [8] Air conditioning module according to one of the preceding claims, characterized by in that the condensate element is designed as a condensate tray (46) which is assigned to the external heat exchanger (22), wherein the condensate tray (46) has at least one air outlet (56) which is in flow connection with the internal air duct (10) downstream of the internal heat exchanger (12). [9] Air conditioning module according to claim 8, characterized by that the air outlet (56) surrounds a condensate discharge opening (58). [10] Air conditioning module according to claim 8 or claim 9, characterized by that the air outlet (56) is assigned to the switching element (36). [11] Air conditioning module according to one of claims 8 to 10, characterized by that the air outlet (56) is assigned to the external heat exchanger (22). [12] Air conditioning module according to one of claims 8 to 11, characterized by that the air outlet (56) is associated with an outside air inlet (26). [13] Air conditioning module according to one of claims 8 to 12, characterized by that a heating air guide channel (48) is arranged below a bottom surface (50) of the condensate tray (46).

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